This application claims priority from Korean Patent Application No. 2004-87396 filed Oct. 29, 2004, incorporated herewith by reference in its entirety.
1. Field of the Invention
The present invention relates to a heat exchanger, in which the flow of a heat exchange medium flowing through tubes is selectively controlled, and opened and closed in order to control heat exchange capability according to cooling and heating loads. More specifically, the invention relates to a heat exchanger, in which one distribution hole is constructed for one tube, so that temperature can be minutely controlled with small temperature deviation in each step, and the opening and closing method of the distribution hole is configured in a sliding type that uses a slide valve, so that the shapes of a header and a tank are simplified, and a clamping operation is also improved.
2. Background of the Related Art
As is well known generally, an air conditioner includes a cooling system and a heating system. The cooling system is configured so as to cool the inside of a vehicle by the heat exchange of an evaporator through a circulating process of a heat exchange medium discharged by the drive of the compressor, the heat exchange medium flowing into the compressor again by way of a condenser, a receiver drier, an expansion valve, and an evaporator. The heating system is configured so as to flow a heat exchange medium (engine coolant) into a heater core in order to exchange heat, and warm the inside of a vehicle.
The condenser, the evaporator, and the heater core that exchange the heat of a heat exchange medium are heat exchangers. Such heat exchangers are supplied with a heat exchange medium, exchange heat to an appropriate temperature, and circulate the medium.
As shown in FIG. 1, the conventional heat exchanger described above includes a plurality of tubes 5 arranged spaced apart from one another at a regular intervals in such a fashion that both ends of each tube are fixed to upper and lower headers 1 and 3, respectively, upper and lower tanks 7 and 9 coupled to the upper and lower headers 1 and 3, respectively, for defining passageways fluid-communicated with the apertures of the end portions of each tube 5 together with the upper and lower headers 1 and 3, and heat radiating fins 11 installed between two adjacent tubes 5 for widening a heat radiating surface area of the heat exchanger.
In the conventional heat exchanger configured as described above, at a state where the heat exchanger is mounted on an air conditioner, specifically an air conditioner for a vehicle, the heat exchange medium, which is supplied to the passageway defined by the upper tank 7 and the upper header 1, performs heat exchange while passing through the tubes 5 at one side partitioned by a baffle, makes a U-turn at a passageway defined by the lower tank 9 and the lower header 3, performs again heat exchange while passing through the tubes 5 at the other side at this point, and is discharged through the passageway defined by the upper tank 7 and the upper header 1.
In the conventional heat exchanger in which heat exchange is performed as described above, a heat exchange medium (the coolant of a vehicle) is supplied regardless of heating or cooling loads, so that a separate control means is needed in order to arbitrarily control heat exchange capability according to heating or cooling loads. For example, in the case of a heat exchanger used as a heater core of a vehicle, in order to control the heat exchange capability of the heat exchanger, a method has been used for controlling the volume of air passing through the heat exchanger by controlling the rotating speed of a blower or installing a door at the front side of the heat exchanger. An additional device is required in order to control the heat exchange capability of the heat exchanger by controlling the air volume as described above, so that the control is not reliably performed.
In order to address and solve the above problem, as shown in FIGS. 2 and 3, the inventor proposed an apparatus including a plurality of tubes 5 arranged spaced apart from one another at regular intervals in such a fashion both ends of each tube are fixed to upper and lower headers 1 and 3, respectively, a division and supply means 13 connected to the upper header 1 for supplying a heat exchange medium to a specific tube 5, and a lower tank 9 connected to the lower header 3 for defining a passageway fluid-communicated with an aperture of the end portion of each tube 5 together with the lower header 3. (refer to Korean Patent Reg. No. 170234)
The division and supply means 13 includes a plurality of connection passageways 15 defined therein so as to be fluid-communicated with an aperture of the upper end portion of each tube that is coupled to the upper header 1, a main body 17 having a cylindrical heat exchange medium divider 19, in which the inlet side of the connection passageway 15 is formed within a certain angle range, at least one heat exchange medium supplying pipe 21 installed so as to be fluid-communicated with the cylindrical heat exchange medium divider 19 formed at the main body 17, a rotating member 23 rotatably installed at the cylindrical heat exchange medium divider 19, the rotating member having a rotation axis 25 and a blocking collar 27 installed at the rotation axis 25 for selectively blocking the inlet of the connection passageway 15 fluid-communicated with the heat exchange medium divider 19, and a covering member 29 for supporting the rotation axis 25 and blocking the heat exchange medium divider 19.
In order to exchange heat with the heat exchange medium using the heat exchanger in the state described above, first, the heat exchange medium is supplied through the heat exchange medium supplying pipe 21, and the rotating member 23 rotatably installed at the heat exchange medium divider 19 is rotated according to the load applied to the heat exchanger. Then, the blocking collar 27 selectively opens and closes the inlet of the connection passageway 15 in response to the rotation of the rotating member 23, and thus the heat exchange medium is supplied to some tubes 5, or all the tubes 5.
In the case where the inlets of the connection passageway 15 are formed at both sides, the blocking collars 27 installed at both sides of the rotating member 23 open the end portions of each tube 5 at the same time, and thus some tubes 5 can be supplied with a heat exchange medium. The supply amount of the heat exchange medium is controlled according to the rotation of the rotating member 23, so that the heat exchange capability of the heat exchanger can be controlled arbitrarily.
As described above, the heat exchange medium can be selectively flown into each tube 5 of the heat exchanger, and thus the performance of the heat exchanger can be arbitrarily controlled, so that heating or cooling load can be easily coped with.
The heat exchanger is advantageous in that the amount of the heat exchange medium can be selectively controlled. However, the heat exchange medium guided by the blocking collar 27 of the rotating member 23 mostly flows into the tubes placed at one side, so that the mixing performance of the heat exchange medium is degraded, and, since the temperature deviation in each step is large, the temperature cannot be minutely controlled.